Central muffler



FIG. 1 is a bottom plan view of a central muffler showing my new design, it being understood that the top is a mirror image thereof;

FIG. 2 is a perspective end view thereof, seen from the left of FIG. 1; and

FIG. 3 is a perspective end view thereof from the end opposite that shown in FIG. 2. 

The ornamental design for a central muffler, as shown and described. 